New Petzl Duo S

“Candles are by common consent the most dependable illuminant, as they cast no treacherous shadows, though electric torches are a good standby”

H.E. Balch. Mendip: Its Swallet Caves and Rock Shelters.

Those cavers with middling-long careers will remember the occasionally reliable Oldham cells of the ’80s, with their array of bulbs – Krypton, Halogen – and their fuses that could be bodged with the silver paper from Kit Kat wrappers. Coming into the UK this week is a new light by Petzl, the Duo S, which still has an array of ‘bulbs’ – well, LEDs – but can no longer be fixed by a Kit Kat wrapper…

The fuller specification is on the website, under the ‘Lights…’ section. Here it’s probably sufficient to say, it does a lot! Rather than repeat the facts (there’ll be lots of blurb online soon anyway), I’ll stick a couple of opinions on here (my own, and to be taken with the appropriate pinch of salt).

The current Petzl range of lights useful for caving seems to be:

1. Pixa 2, a light for centre use because it is bright enough (especially in smaller group-friendly caves, where clients work in groups of eight – twelve) without giving any battery-draining or instructor-blinding options. It has headtorch and helmet mounting options so it can double up for caving and night walks, and it can run off rechargeable and also prime AA cells, useful for times of power cut or charger failure.

2. Pixa 3, a light for club use because it gives 100 lumens (*how* much brighter than an FX2?), can be managed by sensible novices to balance run-time with appropriate brightness, and is relatively cheap – certainly for a reliable, cave appropriate unit. Running on AA cells, it is easier for a club equipment officer to manage than lithium-ion cells – if a charger doesn’t work then the local supermarket will see you for the weekend. The mounting options also make it a useful spare light, as it can be handed over to a lightless caver to fit to their helmet quite easily. Plus, it’s a perfectly good headtorch for walking back from the pub with. Incidentally it has a niche for taking on expeditions where your main light is run on a rechargeable lithium -ion array, but if the generator or solar panels fail, then at least you can still go caving. We’ve seen the Pixa 3 going to Meghalaya on the strength of this.

3. Duo Z2, a light that Petzl market as being for general use, as it runs on four AA batteries and comes within most non-student-cavers’ budgets. It has lots of nice features, but in my opinion its performance is entirely defined by the choice of power source. The given run times are 15 hours 30 minutes at 50 lumens (ambient); 6 hours 45 minutes at 120 lumens (proximity); and 2 hours at 220 lumens (movement). In context, that’s about an OFD 1 – Top Entrance trip without a battery change, with a bit of care; assuming that your rechargeables are giving as good performance as prime AA cells – Petzl don’t specify the batteries that give these results but let’s assume they’ve not chosen duff ones! It’s the usual story, you won’t get lithium-ion performance out of a sane number of nickel-metal-hydride cells; you’ll limit brightness or else you’ll limit duration. What you do get, is a significant up-front price saving – cells and chargers don’t come cheap, if you want ones that don’t blow up! Also, here, you get a high-end primary light that you can take anywhere that AA cells are available; this may be helpful if you are worried about flying with lithium-ion cells on an expedition. You’ll want battery sponsorship, and possible a team of porters to carry your spare cells, but at least you’ll have a bright light to cave on despite the worst efforts of customs officials or your expo nerd who has killed the solar panels… So if anything, I’d suggest that this is a specialist light primarily, for a subset of expeditioners flying outside of Europe; with maybe a place in the kit store of UK based cavers who want a nice bit of kit but don’t do very long or regular trips, where the battery duration / ongoing running costs will start to kick in.

4. Duo S, the new Petzl high-end caving torch, which effectively replaces the Rush, Vario etc. It runs off the same ACCU 2 (with options for ACCU4) rechargeable lithium-ion cells as its precursors; so if you had one of these but fancy the latest kit, you’ll have a spare battery and charger which can’t be bad. The brightness of the Duo S is impressive, the price is competitive for this level (the three year warranty on the lamp is nice), and the weight on the head is attractive for those who have reason to worry about this. Petzl have made a decision to keep with the ACCU 2 as standard and it should be fine for UK use; 700 lumens for 3 hours 30 minutes, 330 lumens for 6 hours and so on should be enough for most light junkies. For trips abroad it gets to be more of a balancing act. You’ll probably want more than one battery for a trip down the Berger, for instance – this is not a challenge! – and a prolonged underground camping trip might call for a significant investment in spare cells; or else you’ll need to be parsimonious with your light. We’ll probably do a ‘buy four batteries at a discount’ or similar at some point to help those who want to club together for an expo. I think that there’s a sliding scale between those whose summer involves caving in Matienzo, the Vercors or similar – excellent caving where few trips are longer than twenty four hours, rechargers at the gite – and those whose holiday consists of living on top of a mountain where power supply is imperfect, and staying underground for four days or more. Very much a decision based upon one’s caving preferences and ambitions. The only other factors to bear in mind when thinking about the Duo Z2, the Duo S, or anything else, is the IPX67 (waterproofness) rating on the Duo, which is fine for most caving but really isn’t diveable; and also that the two Duos *don’t* allow changing from one battery source to another; at the moment the DuoS runs on the ACCU2 (or ACCU4) but it cannot be made to run off anything else like a AA or 9v cell.

SO! These are my current meanderings on the latest Petzl line up. I’ve not talked about the liminal models that are used down caves – sometimes quite successfully, like the various Tikkas or Myos, which would extend the discussion to even greater lengths! I’m very glad that Petzl have re-engaged with proper, designed-for-purpose-caving lights. For most of the last decade we had a mantra of asking our Petzl dealer “what is going to replace the Duo?” every spring. How people like the new ones, and how they go in real life, we’ll see; but at least they really are quite distinctly new, and I think they have a place in the considerations of new cavers, and those looking to upgrade.